An Optical Transport Network (OTN) is comprised of a plurality of switch nodes linked together to form a network. The OTN includes an electronic layer and an optical layer. The electronic layer and the optical layer each contain multiple sub-layers. The optical layer provides optical connections, also referred to as optical channels or lightpaths, to other layers, such as the electronic layer. The optical layer performs multiple functions, such as monitoring network performance, multiplexing wavelengths, and switching and routing wavelengths. In general, the OTN is a combination of the benefits of SONET/SDH technology and dense wavelength-division multiplexing (DWDM) technology (optics). OTN structure, architecture, and modeling are further described in the International Telecommunication Union recommendations, including ITU-T G.709, ITU-T G.872, and ITU-T G.805, which are well known in the art.
The construction and operation of switch nodes (also referred to as “nodes”) in the OTN is well known in the art. In general, the nodes of an OTN are generally provided with a control module, input interface(s) and output interface(s). The control modules of the nodes in the OTN function together to aid in the control and management of the OTN. The control modules can run a variety of protocols for conducting the control and management of the OTN. One prominent protocol is referred to in the art as Generalized Multiprotocol Label Switching (GMPLS).
Generalized Multiprotocol Label Switching (GMPLS) is a type of protocol which extends multiprotocol label switching (MLS) to encompass network schemes based upon time-division multiplexing (e.g. SONET/SDH, PDH, G.709), wavelength multiplexing, and spatial switching (e.g. incoming port or fiber to outgoing port or fiber). Multiplexing is when two or more signals or bit streams are transferred over a common channel. Wave-division multiplexing is a type of multiplexing in which two or more optical carrier signals are multiplexed onto a single optical fiber by using different wavelengths (that is, colors) of laser light.
RSVP and RSVP-TE signaling protocols may be used with GMPLS. To set up a connection in an Optical Transport Network, nodes in the Optical Transport Network exchange messages with other nodes in the Optical Transport Network using RSVP or RSVP-TE signaling protocols. Resources required for the connection are reserved and switches inside the network are set. Information sent by signaling protocols are often in a type-length-value (TLV) format. The same protocols may also be used to take down connections in the Optical Transport Network when the connections are no longer needed.
OSPF and OSPF-TE routing and topology management protocols may also be used with GMPLS. Under OSPF protocols, typically each node in an Optical Transport Network maintains a database of the network topology and the current set of resources available, as well as the resources used to support traffic. In the event of any changes in the network, or simply periodically, the node floods the updated topology information to all the Optical Transport Network nodes. The nodes 20 use the database information to chart routes through the Optical Transport Network.
Traffic Engineering (TE) is a technology that is concerned with performance optimization of operational networks, such as OTNs. In general, Traffic Engineering includes a set of applications, mechanisms, tools, and scientific principles that allow for measuring, modeling, characterizing and control of user data traffic in order to achieve specific performance objectives.
Current Traffic Engineering practices have been utilized to increase the data rates in networks. However, future information transport systems are expected to support service upgrades to data rates of one terabyte per second (Tbps) and beyond. To accommodate such high rates in transport network architectures, multi-carrier Super-Channels coupled with advanced multi-level modulation formats and flexible channel spectrum bandwidth allocation schemes may be utilized. However, the coexistence of super-channels using different modulation formats on the same optical fiber network infrastructure may have a detrimental effect on the Optical Signal to Noise Ratio (OSNR) of adjacent Super-Channels due to interference such as cross-phase modulation. Therefore, it may be desirable to be able to evaluate the mutual impact of existing and new Super-Channels on each other's quality of transmission (for example, bit error rate) before establishing new Super-Channels.
The present disclosure addresses this need with methodologies and systems using new Super-Channel Parameters GMPLS signaling and routing extensions to convey optical signal attributes and in-use slice information of Super-Channels.